Gas and liquid contact apparatus



Dec. 2s, i948. D, R. GRAHAM f 2,451,658

GAS AND LIQUID CONTACT APARATUSQ Dec. 28, i948. D. F. GRAHAM Y GAS AND LIQUID CONTACT APPARATUS Filed sept. `12, 194e -5 Sheets-Sheet 2 INVEN-ron ,Zawd/D, Gf?

D. P. GRAHAM l GASVAND LQUID CONTACT APPARATUS Dec. 289" E948.

5 Sheets-Sheet 5 Filed Sept. l2, 1946 I mvENToR Za wd P rabe/7,7'

ORNEY Dea. 2g, g, D, P, GRAHAM 2457,658

GAS AND LIQUID CNTACT APPARATUS Filed Sep. l2, 1946 5 Sheets-Sheet 4 V K K QW; f INVENTOR I f jaa/zd' Tf'cz ham ORNEY Dec. 28, 1948. D. P.) GRAHAM v'GAS AND LIQUID CONTACT APPARA'IS 5 Sheets-Sheet 5 Filed Sept. 12, 1946- INVENTOR ,Za wd l? 'raam ZODB.

Patented Dec. 1948 UNITED sTATEs PATENT oFFlcE GAS AND LIQUID CONTACT APPARATUS David P. Graham, Westbury, N. Y., asaignor to Peabody Engineering Corporation, New York, N. Y., a corporation of New York 6 Claims. l

This invention relates to gas and liquid contact apparatus of the type having one or more diaphragms containing apertures forming oriilces through which the gas passes upwardly at a velocity suited to prevent the liqud on the diaphragms from passing downwardly through said orifices. Such apparatus may be for cleaning or cooling gases or for liqud-gas contact' purposes. An apparatus of this general type is disclosed in U. S. Patent No. 2,319,814 to R. R. Harmon, dated May 25, 1943.

An object of the present invention is to provide novel and improved means for washing the undersides of the orice plates in an apparatus of the above type.

Another object is to provide novel and improved I apparent as the nature of the invention is moreA fully disclosed.

In accordance with the present invention, a spray zone is located beneath each separating This spray zone comprises a diaphragm extending across the apparatus and adapted to hold a predetermined depth vof liquid thereon. The diaphragm contains aspirating slots through which the gas travels upwardly at a velocity sumcient to keep the liquid from flowing downwardly through the slots. As the gas travels upwardly through the slots, however, it picks up liquid droplets from the layer of liquid on the diaphragm to thereby form a spray. Passages are formed above the slots by vertical spaced plates which extend downwardly towards the diaphragm, but are spaced sufilciently therefrom to permit the liquid to pass beneath the lower ends of the plates into the rising gas stream. The aspirated liquid and gas rising through these passages become intimately mixed in the form of a spray and the passages are arranged to direct this spray onto the underside of the orifice plate of the next cleaning zone.

The aspirating slots are preferably rectangular in shape and the spray passages are made similar in shape so as to eifect maximum turbulence and maximum uniformity of the spray.A

The slots preferably extend radially of the diaphragm. They may, however, be otherwise disposed, such as circularly or circumferentialiy,

Application september 12, 194s. semi Nn. 696.605

(cl. zel- 113) depending upon the construction of the apparatus. Likewise, the plates forming the spray -passages may converge or diverge upwardly as required in order to eiiect the maximum dispersion of the liquid in the rising gas stream.

Although the novel features which are believed to be characteristic oi' this invention are pointed out more particularly in the claims appended hereto, thenature ofthe invention will be better understood by referring to the following description. taken in connection with the accompanying drawings in which a specic embodiment thereof has been set forth for purposes of illustration.

In the drawings: l

Fig. 1 is a side elevation of a gas scrubber embodying the present invention;

Fig. 2 is a vertical sectionrthrough a portion of the gas scrubber taken on a larger scale;

Fig. 3 is a horizontal section on a still larger scale taken on the line 3-3 of Fig. 2;

Figs. 4 and 5 are vertical radial sections taken on the lines 4 4 and 5-'5 respectively of Fig. 3;

Fig. 6 is a partial vertical section taken on the line 6-6 of Fig. 3;

Fig. 7 is a partial horizontal section taken on the line 'l-'I of Fig. 2. but on the same scale asv Figs. 8 and 9 are vertical radial sections taken on theiines 8 8 and 9-9 respectively ofFig. 7; and

Fig. 10 is a partial vertical section taken on the line lil-I0 of Fis. '1.` f

Referring to the drawings more in detail, the invention is shown as embodied in a gas scrubber comprising a vertical cylindrical casing or shell I0 having a lower spray-forming zone I I (Fig. 2), a plurality of spraying zones l2, a plurality of cleaning orrcooling zones I3, a liquid inlet zone Il, an entrained moisture-eliminating zone l5. and an upper gas outlet duct I6. The shell l0 is provided with cleaning openings I1 at the various zones which are closed by removable covers i8.

The entralned moisturereliminating zone Ii lliquid inlet zone I4 through a supply duct 25 which extends from the shell I@ to a central cup 23 supported by struts 21 from the plate 2 I. The cup 26 opensdownwardly into a receiver 28 which is attached thereto' and carries a plurality of 5 radial perforated pipes 29 which are supported by struts 30. The pipes 29 communicate with the receiver 28 and are perforated to discharge the liquid onto the top cleaning or cooling zone I3.

Each cleaning or cooling zone I3. as shown in l Figs. 2 to 6, comprisesacentral imperforate diaphragm 3l supported by a plurality of radial struts 32 which are attached at their outer ends to the shell I0. Pie-shaped perforated plates 33 having orifices 34 therein (Fig. 3) are attached 15 to the central diaphragm 3l, 'radial struts 32 and to a peripheral ange 35. Baiile grids 3S having baiiies 31 which are disposed above each oriilce 34 are positioned' above and secured to the orifice plates 33. The bailles 31. are so arranged that the gases passing upwardly through the orifices 34 impinge thereon.

The radial struts 32 constitute drain troughs through which the liquid ows downwardly from one zone to the next. These troughs comprise plates 4I) and 4I (Fig. 6) secured by suitable means shown as bolts 42 and spaced to receive liquid therebetween. The plate B0 terminates at its lower end in a bottom lip 43 having an upstanding rim 44 forming ra trough in which the 30 liquid is received and is maintained at a height to form a liquid seal with the bottom edge of the plate 42. The liquid overflows the rim- 44 onto the next lower zone. The construction of the cleaning and cooling zone is similar to that disclosed in the Harmon patent above referred to.

secured at their outer ends to the shell I0. Pie- 45 shaped plates 52 are secured to the central diaphragm 5I), struts 5I, and to a peripheral flange 53 attached to the shell Ill. These plates 52 are imperforate except for central radial rectangular slots 54. The diaphragm 501s also shown as provided with radial slots 55 in alignment with the radial slots 54 in the plate 52. The diaphragm slots may, however. be omitted if desired.

Rectangular members 56 having side walls 51 and end walls 58, dening a rectangular passage 55 A59, are disposed above the plate 52 with the paissages 59 registering with the slots 54. The lower ends of the walls 51 and 58 are spaced above the plate 52 to form an opening BIJ for the passage of liquid. The members 56 are supported by 00 brackets 6I attached to the plate 52. In the embodiment shown the side walls 51 are parallel to each other, although they may diverge or converge upwardly as re'quired to produce a spray having the required characteristics.

Similar members B2 Vhaving side walls 63 and end walls 64 dening passages 65 are supported on the diaphragm 50 by brackets ,6B with their passages 65 registering with the slots 55. The

4 d 33 and are disposed in a radial position to register with the radial center line of said orifice plates.

The radial struts 5I are formed by side walls 10 and 1I which are spaced apart and secured by suitable means shown as bolts 12 and are attached at their upper edges to the plate 52 in a position to receive liquid which is discharged from said plate. The wall I0 is shown as provided with a bottom lip 13 having a rim 14 extending therearound and overV which the liquid is discharged. The rim 14 is of a height to form 'A a liquid seal with the lower edge of the wall 1li..A

A weir 15 is attached to the plate 52 and is disposed around the opening to the discharge duct formed by the struts 5I. The Weir 15 determines the level of liquid on the plate 52 and is of such height that a liquid head is maintained at the 8U is provided with an inner circular ilange 8l f dening a central opening 82 through which the gas passes upwardly. The ange 3| is adapted to maintain a liquid head at the yentrance to the tubes 19.

Gas for cleaning or cooling is supplied to the shell I0 through a supply duct 8 5 (Fig. 1) at a point beneath the spray vzone I I. A by-pass duct 86 connects the duct 85 with the duct 11 to supply a portion of the inlet gas to the ring 16. The `lower end of the casing I 0 communicates with a discharge pipe 88 which may be controlled by the usual valves, not shown.

i Operation A In the operation of this device. the gas which is to be cleaned or cooled is supplied to the duct and the major portion of this gas enters the lower zone of the shell I0 and passes upwardly through the opening 82. A portion, however, is by-passed by the duct 83 and enters the gas ring 18. Liquid is supplied through the duct 25 and enters through the receiver 28 and pipes 29 from which it is discharged onto the top cleaning zone v I3 and flows down from zone to zone through the v at a velocity which prevents the liquid from flowlower ends of the members 62 are spaced from 70 the surface of the diaphragm 5U to form liquid passages 61. The members 56 and 62 extend upwardly to direct a spray from the passages 59 and 65 upwardly against the under surface of the orifice plates 33 of the adjacent cleaning zone 75 ticles are entrapped and removed by the liquid blanket and the cleaned gas continues upwardly, while the liquid with the entrapped particles flows downwardly through the drain passages onto the plates of the nextzone.

In the spray-forming zones l2 a liquid blanket is maintained on the plates 52 to a height which is determined by the height of the weirs 15. Any excess liquid flows downwardly over theweirs and through the drain passages between the walls 10 and 1| and'over the rims 14'onto the plates of the next zone. At the same time the gases'whichare dowing upwardly lat high velocity pass iiowing downwardly through these slots. However, the liquid head, due to the height ofthe weirs 15, tends to cause the liquid to iiow through the passages 60 at a rate depending upon the head -which is'thus maintained and on the size of the passages 60. The gases whichare passthrough the slots 54, and prevent the liquid from velocity, passes outwardly from-the top of the y passages 59 'and impinges-on the bottom ofthe orifice plates 33 of the cooling and washing zone next above.

The arrangement is such that the spray is dispersed uniformly across the bottom of the orilice plates 33 for washing the same. A portion of this liquid is carried upwardly through the orifices 34 with the rising gases. The major portion, however, after washing the bottom of the oriiice plates, falls back into the blanket of water which is maintained upon the plates 52.

By the spray-forming mechanism above described, it is possible to completely wash the underside of the various orifice plates without the use of special spray apparatus such as pumps or rotating nozzles as the velocity of the gas itself is utilized for producing the spray'and causing the same to impinge upon and wash the orice plates.

The liquid overiiowing from the lowest spray zone I2 falls onto the plate 80. The liquid level on the plate 80 is maintained above the tops of the tubes 19 so as to provide a head to force the liquid into said tubes. The incoming gases from the gas ring 16 flow downwardly through the openings 18 and the tubes 19 at a high velocity and in so' doing pick up liquid droplets which have entered the tubes 19 and produce a spray. This spray then partially washes the portion of the gases in the lower zone of the shell i0 and any that is entrained passes upwardly through the central opening 82 with themain gas stream. The liquid which overflows the lip 8l accumulates viine particles and to thereby facilitate their subsequent removal in the cleaning zones.

The quality of the spray may be varied by adjusting the height of the weirs 15 and the spacing of the walls 51 and 58 from the plates 52, and by adjusting the gas velocity.

Although certain speciiic embodimentsv of the invention have been shown for purposes of illustrationit is to be understood that the invention is capable of various'uses and that changes and' adaptations may be made therein as will be readily apparentto a person skilled inthe art. The invention is only to berestricted in accordance withthe scope ofthe following claims.

What is claimed is:

1. In a gas andlliquid contact apparatus, a

. treating zone comprising an orifice plate carrying a blanket of liquid and containing orifices through which the gas to be treated passes upwardly at a rate to prevent downward flow of the liquid therethrough and baiiles over said oriccs against which the gases impinge, and a spray zone beneath said .treating zone, said spray zone comprising a diaphragm having openings through which said gas passes upwardly, means maintaining a blanket of liquid on said diaphragm and means forming unobstructed passages extending upwardly above saidv openings and registering therewith, saidl means having anopening into said liquid blanket to permit liquid to flow into lsaid passages and to be picked up by the rising rate to prevent downward ow of the liquid in the bottom of the shell and is discharged'together with its accumulated impurities through therethrough and baiiles over said orices against which the gases impinge, and a spray zone beneath said treating zone, said spray zone comprising a diaphragm having openings through which said gas passes upwardly, means maintaining a blanket of liquid on said diaphragm, members forming open-ended passages extending upwardly above said openings and registering therewith, said members having their lower ends Vextending into said liquid blanket but spaced above said diaphragm to permit liquid to ow into said passages and to be picked up by the rising gas therein to form a spray, said members having their upper ends positioned to discharge the spray onto the under surface of said oriilce plate.

3. In a gas and liquid contact apparatus, a treating zone comprising an orifice plate carrying a blanket of liquid and containing orifices through which the gas to be treated passes upwardly at a rate to prevent downward ilow of the liquid therethrough and baiiles over said orifices against which the gases impinge, and a spray zone beneath said treating zone, said spray zone comprising a diaphragm having elongated slots through which said gas passes upwardly, means maintaining a blanket of liquid on said diaphragm and members forming open-ended passages exor of any other cross section if desired in anytending upwardly above said slots and registering therewith, said members having their lower ends extending into said liquid blanket but spaced from said diaphragm to permit liquid to flow into said passages and to be picked up by the rising gas therein to form a spray, said members havir g their upper ends positioned to discharge the spray onto the under surface of said oriiice plate.

4. In a gas and liquid contact apparatus, a

the under surface of said oriilce 7 treating zone comprising an oriice plate carrying a blanket of liquid andv containing oriilces'through which the gas to be treated passes upwardly at a rate to prevent downward ilow of thel liquid therethrough and baffles over said orices against which the gases impinge, and a spray zone lee--v neath said treating zone,- said spray zone comprising a diaphragm having Aopenings through which said gas Passes upwardly, liquid drain passages communicating with said diaphragm to discharge excess liquid therefrom, weirs surrounding said drain passages for maintaining a blanket oi' liquid of apredetermined depth onl saidv diaphragm. and means forming lunobstructed passages extending Vupwardly above said openings and registering therewith, said means having an a rate to prevent-downward ow' of the liquid therethrough and names over said oriiices against which the gases impinge, said spray zone comprising a central diaphragm and a plurality of radial struts supporting the same, a plate secured to said central diap and to said struts, liquid discharge means associated with said struts to discharge liquid from said spray zones, weirs associated with said discharge means to maintain a liquid blanket of a predetermined depth on said plate, said plate having slots therein through which said gas passes upwardly at a velocity suited to prevent downward now of liquid therethrough, and means formingA unobstructed passages extending upwardly above said slots and registering therewith, said means having an tov ow into said passages and to be picked up by 1 8 opening into said liquid blanket to permit liquid the rising gas therein to iorm a spray, said pasv sages being positioned to discharge the spray-ontol the under surface of said orice plate.

6. In a gas and lliquid contact appparatus, a

treating zone comprising an oriilce plate vcontaining orices through which the gas to be treated r.passes and having bailles over said -orificesvadjacent which the gases impinge, and a spray zone -beneath said treating zone, said spray zone comprisngl a central diaphragm and a" plurality vof radial struts supporting the same, a plate securedto said central diaphragm and to said struts, liquid discharge means associated with said'struts to discharge -liquid from said spray a liquid blanket of a predetermined depth on said plate, said plate having slots therein through zones, weirs associated with said discharge means to vmaintain which said gas passes upwardly at a Vvelocitysuited to prevent downward ow of liquid therethrough, and means forming unobstructed passages extending upwardly above said slots and registering therewith, said means having an openingiinto said .liquid blanket 4to permit liquid to flow into said passages and to b'e picked upV by the rising?V gas therein to form a spray, said passages being positioned to discharge the'spray onto the under Y surface of said orifice plates for washing the Same.

'REFERENCES crrap The following references are UNITED STATES lPATENTS of record in kthe Y naief DAVID P. GRAHAM. I 

